https://github.com/M-o-a-T/moat-victron/blob/main/scripts/
My "build_image" script creates a hybrid image that's capable of booting both Debian and Venus from the same file system, using btrfs and subvolumes.
The script does this:
- create a boot partition (with the Debian kernel)
- create a root supervolume
- copy Debian to a subvolume
- copy Venus to another subvolume
- reflink-copy the kernel modules from Debian to Venus
- create an empty subvolume, for /data
- modify /etc/fstab appropriately
- tag the Venus subvolume as default
Usage:
- download a Debian for your Raspberry Pi from https://raspi.debian.net/
- download a Venus image (*.wic.gz) from https://updates.victronenergy.com/feeds/venus/release/images/raspberrypi2/
- Uncompress both images
- Run
build_image deb.img venus.wic /dev/sdX
where /dev/sdX is an SD card of at least 4GB. The card's previous content will be deleted without warning, so be careful. - plug into your Raspberry Pi and boot it. You're in what looks like a standard Venus installation.
- Run the "setupdeb.sh" script.
Mostly-seamlessly running a normal Debian program from within Venus can be done with a helper, named the same as the target program:
#!/bin/sh
exec env PATH=/opt/debian/bin LD_LIBRARY_PATH=/opt/debian/lib/aarch64-linux-gnu/ \
/opt/debian/bin/$(basename $0) \
"$@"
Of course, you also can use chroot; venus and /data can easily be bind-mounted to /opt/debian/whereever, as required. "setupdeb.sh" installs this helper as /usr/local/bin/btrfs because, surprise, there is no btrfs-progs package for Venus.
To switch boot targets, a companion script https://github.com/M-o-a-T/moat-victron/blob/main/scripts/boot_image simply mounts the supervolume and changes the default.
There's also a script to fetch a new Venus image and set it up just right; however that hasn't been tested at all.
All of the above is probably slightly buggy, because I didn't actually run the current incarnation yet (too busy setting up my solar systems ā¦). Bug reports are always welcome and will be acted upon.
